Various kinds of static mixing reactors for mixing at least two kinds of fluids have been proposed. Such static mixing reactors are used to manufacture ultrafine particles through chemical reaction or crystallization. Among the static mixing reactors is a micro-channel reactor for supplying fluids to be mixed into a micro-channel. The micro-channel reactor is attracting attention.
The micro-channel reactor is provided with a micro-channel having a channel width of 10 μm to 1000 μm. In the micro-channel reactor, at least two kinds of fluids diverge and then join each other through the micro-channel. In the micro-channel reactor, the fluids diverge, whereby the distance by which the fluids are diffused is reduced. As a result, the speed by which the fluids are mixed is increased. In the micro-channel reactor, therefore, it is possible to efficiently mix the fluids within a shorter time than when using a conventional static mixing reactor.
A rector having a Y-shaped channel is well known as one example of such a micro-channel reactor. In this type of mixing reactor, a channel into which a first fluid is introduced and a channel into which a second fluid is introduced intersect in a Y shape in order to form a single joining channel. The fluids supplied into the respective channels join each other in a state of laminar flow at a channel intersection part. Subsequently, the respective fluids are diffused and mixed.
FIG. 1 is a photograph showing a conventional stacked type micro-channel reactor.
Referring to FIG. 1, a conventional micro-channel reactor 10 includes an upper plate 11, having a micro-channel in which reactant A flows, and a lower plate 12, having a micro-channel in which reactant B flows. That is, the interface at which the upper plate 11 and the lower plate 12 face each other is provided with an introduction channel, into which fluids are introduced, a mixing channel, in which the direction in which the fluids flows is changed, and in which the fluids are divided into several parts one or more times in order to mix the fluids, and a discharge channel, from which the mixed fluid is discharged. The mixing channel includes a main channel and a branch channel such that, when the upper plate 11 and the lower plate 12 are placed one on another, the fluids alternately flow from the upper plate 11 to the lower plate 12.
In the micro-channel reactor, therefore, the respective fluids are mixed. Mixing behaviors 50 are shown in a typical view of FIG. 2.
Referring to FIG. 2 together with FIG. 1, fluids 51 and 52 introduced into the introduction channel are stacked in a shape as shown in FIG. 2(a). Subsequently, the mixed fluid diverges at a first diverging part. As a result, some of the mixed fluid flows to the main channel, and the remainder of the mixed fluid flows to the branch channel. Subsequently, the fluids join each other again. Since the branch channel is interrupted, the upper fluid and the lower fluid, stacked in shapes as shown in FIGS. 2(b) and 2(c), join each other at the next joining part. As a result, the fluids are stacked as shown in FIG. 2(d). At the third joining part, the mixed fluid has layers as shown in FIG. 2(e). As the result of the repetition of the above process, the mixed fluid has 2n layers at the n-th joining part.
In the micro-channel reactor with the above-stated construction, laminar flows, which form interfaces, are alternately arranged one on another through the structure of the channel configured as described above, thereby accelerating mixing of the fluids.
That is, the micro-channel reactor with the above-stated construction is designed to have a structure that is capable of maximizing mixing between reactants, the reaction products being solutions in most cases. For this reason, stagnation of the reaction products is not an issue. For low-viscosity reactants, therefore, it is possible to enable the reactants to continuously react with each other while maximizing mixing of the reactants. However, the channel discontinuously appears and disappears, with the result that the channel is abruptly changed. In a case in which the reaction products are deposited, therefore, the channel may easily become clogged if the channel has a stagnation point. Furthermore, the micro-channel of the micro-channel reactor has a micro structure. As a result, the channel may be easily clogged. Therefore, there is a high necessity for a micro-channel reactor having a novel structure that is capable of preventing stagnation of reaction products while achieving high mixing efficiency in a case in which the reaction products are solid matter, such as nano particles.